1. Field of the Invention
This invention relates to electrical interconnection systems and, more particularly, to electrical interconnection systems where the terminals of one of the components are to be shorted together until mating with the second component and where the mating components may be positively retained together.
2. Description of the Prior Art
The interconnection system of the present invention may be adapted for use in vehicle airbag systems. These airbag systems typically include an airbag unit mounted within the cabin of the vehicle relative the occupants and a controller which is mounted in a convenient location away from the airbag unit(s). In order to deploy the airbag, a squib is activated by the controller. The squib would typically be included within a base unit upon the airbag unit. The base unit would include an opening for receiving an electrical connector in order to form an electrical path between the squib and the controller. The electrical interconnection system enables the airbag unit and the controller to be independently mounted and later easily interconnected.
One example of an electrical connector suited for interconnecting the controller and the squib within the base is disclosed in UK Application No. 9417215.2, filed on Aug. 25, 1994. This connector comprises a generally T-shaped housing having an upper portion carrying a suppression device and multiple contacts for engaging conductors that are ultimately connected to the controller. The contacts extend into the plug portion and are adapted to mate with the terminals of the squib. The plug unit includes openings for receiving the terminals of the squib, which are typically pins.
While effective electrical interconnection may be established between the conductors that are interconnected to the controller and the terminals of the base by way of the above described connector, it is desirable to assure that the squib can not be activated inadvertently when the connector is not attached thereto. This is typically accomplished by including a shorting function that electrically shorts together the terminals in the base. Known ways to accomplish this include a shorting clip with resilient contact arms that extend along the sides of the opening or cavity wherein the pins are installed. These contact arms are commoned and have a natural first position against the pins. In response to insertion of the connector, they are displaced away from the pins, thereby breaking the commoning and enabling the system. One problem with the present systems is that they typically include a shorting clip disposed within an insulating housing which is then seated within the cavity or opening.
This requires the cavity or opening to be larger than required, thereby requiring the portion of the base unit to be larger than would be required to serve its other functions.
In addition, another feature that may be desirable to incorporate into the interconnection system is to have the connector be positively retained within the cavity. This positive retention could be achieved either by structure that assures that the connector cannot be dislodged from the base without such extensive damage to the interconnection system that it would be extremely difficult to mate another connector or by having a release mechanism incorporated into the system that enables the connector to be separated only in response to an affirmative action. The first solution has the advantage of preventing any dislodgement, thereby requiring the whole system to be replaced. The second system has the advantage of enabling easier servicing, as the whole unit would not have to be replaced because the connector could simply be disengaged. Present positive retention systems have a number of problems. For the purposes of this application, the largest being that the retention features usually are incorporated into the sidewalls of the opening or cavity of the base unit. If the interconnection system includes the above desirable feature of a shorting clip, the two features are now competing for the same space. One system that attempts to solve this problem is presented in U.S. Pat. No. 5,314,345 that includes a separate interlock that is insertable into the system to hold the connector with the base. One problem with this is that during assembly the lock element may have been lost or is forgotten to be installed. In addition, it is a problem with the systems to provide positive retention while still enabling detachment if desired.